Using Encore CS6 and has updated the software to ensure ithere is no issue, I have no problem burning the blu-ray iso but trouble occured after I have created DVD ISO and use Toast 11 Titanium to burn using interior dvd burner. Error kicks in

The Drive Reported an Error:

Sense Key + Medium Error

Sense Code = 0 X 02

No Seek Complete

Second Attend using external bluray burner to burn DVD ISO image with Toast 11 Titanium, same issue. I have use the same DVD ISO and try to burn on my PC, it also gave me an error but can't remember what it says.

Mac Third burn using Encore DVD burn directly to Memorex DVD + R 8.5G gave me Sense Code 52102 as it almost finishing up burning.

I have checked the discussion here but nothing for the Mac user, is anyone can share a thought?

All Blu Ray ISO burnered and worked fine

Single Video burned on Mac Book Internal burner worked also therefore I don't seee there should be an issue with the interior drive itself or am I wrong?

It is crazy as I can burn a single video on the DVD but more videos will not work! I hooked up a new external burner it worked randomly as few copies were corrupted. I did copied the DVD iso onto my PC and burned few copies and again few did not work as I now suspense the combination of bad batch of Memorex DVD and a bad internal DVD drive. That is my guess! Anyone?